Knee crepitus is the medical term used to describe the sound and/or sensation of crunching as the knee joint bends back and forth.
Crepitus can be caused by many things. An occasional pop or grinding sound can be normal, and if it is not accompanied by pain or any other concerning symptoms it is generally considered normal.
If the noise occurs regularly and is painful, however, this might be an indication of something more. Many types of knee problems can cause these painful sounds, including osteoarthritis, rheumatoid arthritis, patellar dysfunction and so on. If regularly occurring knee popping noises can be noticed, which are painful and/or accompanied by swelling, it is advisable to seek a medical evaluation.
Symptoms of Crepitus in the Knee
Unique symptoms of knee crepitus caused by arthritis include:
- Unlike a mechanical popping where this popping sensation is painless and intermittent, the crepitus caused by arthritis is oftentimes painful. Also, these symptoms are usually associated with other knee symptoms suggestive of arthritis, such as pain while walking, occasional swelling of the knee, stiffness, and so on. The most common initial location of arthritis in the knee is on the inside aspect of the knee.
- The sound of knee crepitus may be quite soft, but the crunching sensation is often palpable. It can be felt by placing the hand on the knee while flexing and extending the joint. Many things can cause this sensation while flexing and extending the knee and it’s hard to tell without a full exam of the knee if this might be arthritis of the knee or other more innocent causes such as patellar motion.
Knee Crepitus Treatment
As described above, the key feature that concerns clinicians is if the grinding sensation is associated with any other concerning symptoms such as pain, swelling, or locking of the knee. Most people experience the occasional pop or grind, especially when kneeling to the floor or with repetitive knee extension and flexion. If it’s painless, usually it is not a concern. If there are other symptoms, however, it is generally advisable to seek a diagnosis with an appropriate health care professional.
- For a full review of knee arthritis symptoms, see Knee Osteoarthritis Symptoms.